The longest-running civil war in the hemisphere may be over. Negotiators in Havana have reached an agreement between the Colombian government and FARC after 52 years of war, a conflict that had repercussions throughout the hemisphere. The big question will be whether it sticks:

The two sides made the announcement in Cuba, where the negotiations began in 2012 and where Fidel Castro launched a communist revolution that inspired guerrilla insurgencies across the hemisphere. Colombia, a nation of 50 million that is among the closest U.S. allies in Latin America, is the one place where war has yet to end.

“We have finished fighting with weapons and will now do battle with ideas,” said FARC’s chief negotiator, Iván Márquez, a former member of Congress who took up arms after many other leftist Colombian politicians were assassinated by right-wing groups in the 1980s.

In their statements, the two negotiators described the accord as a road map for the transformation of Colombia, ending a sordid history of political violence and creating a more democratic society in a country long dominated by a well-to-do elite.

“This is the final chapter of the Col War in the hemisphere,” US envoy Bernard Aronson told the Washington Post, and it has been a very long chapter. It began in 1964 at the height of the superpower battle, just two years after the Cuban missile crisis. It will end, assuming that both sides adopt their new agreement, 27 years after the fall of the Berlin Wall.

That may be a large assumption. Former president Alvaro Uribe has begun organizing opposition to the deal, which will be ratified (or not) in a national referendum on October 2nd. Uribe has opposed the Havana talks since they began, and has spent the last few weeks building support to defeat it. So far that’s been an uphill struggle, but Uribe may have an opening:

Many Colombians are unhappy, according to surveys. Crime and drug trafficking are on the rise. Economic growth has slowed, and inflation is driving up food prices. Santos’s critics say he has been too distracted by the negotiations with the FARC — which are taking place in faraway Havana, largely in secret — to fix Colombia’s problems.

That secrecy has further contributed to the credibility gap plaguing Santos, as has the nagging perception that he rode Uribe’s popularity into office and then betrayed him. “I don’t trust Santos. This whole thing feels false to me,” said Cali resident Adriana Corrales, 33, referring to the peace deal. …

It’s difficult to know whether Colombians in such areas will vote for a peace deal — war has gone on for so long that few may be willing to believe it could end with a piece of paper.

That may be Santos’s biggest problem here in Colombia’s Valle del Cauca department, including towns such as Pradera that have long lived under threat of guerrilla takeover.

So what’s actually in the peace deal? No one outside of the negotiating group in Havana knows entirely what the agreement contains [see update]. The Washington Post reports that FARC will be given a number of non-voting seats in the national Congress to monitor implementation of the accord, and that rebel commanders not found guilty of war crimes will be allowed to run for office while lower-level fighters will receive a blanket amnesty from rebellion charges. Disarmament won’t take place until after the plebescite, however.

A text of the peace deal will be forthcoming in the next few days, which doesn’t leave a lot of time for debate before President Juan Manuel Santos’ desired October 2nd referendum date. Colombians who look across their border to see the results of victorious socialism in Venezuela may well worry that Santos might deliver them into similar poverty. On the other hand, after 52 years of war, Colombians may be so eager to try something else that they’ll sign off on whatever Santos brings back.

Update: The Post’s report said that the full terms of the agreement hadn’t yet been released, but they have been published in Spanish here. Thanks to Doug Farnes on Twitter for the correction.